stellar evolution(double) Flashcards
(9 cards)
What property of a star does its colour tell us?
The colour of a star tells us about its surface temperature.
True or False? The hottest stars are red.
False. The hottest stars are blue, whereas the coolest stars are red.
Which has a hotter surface temperature, a red giant or a white dwarf?
A white dwarf has a hotter surface temperature than a red giant.
True or False? As a star expands, its surface cools and becomes redder.
True.
True or False? All stars form from a cloud of dust and gas which becomes a protostar and then a main sequence star.
True.
What forces, including their direction, act when a star is in a stable state?
Inward gravitational force, outward pressure from fusion reactions.
Name the stages, in the correct order, in the life cycle of a star similar to the Sun.
Nebula → Protostar → Main sequence → Red giant → White dwarf.
When does a protostar become a main sequence star?
When nuclear fusion starts and gravity is balanced by fusion pressure.
When does a main sequence star turn into a red giant?
When hydrogen runs out in the core and fusion of helium begins.
